Getting to the bottom of Data Link: Ground Radar and Lightnings

[ScottBouch]

Hi all,

I know this topic has come up in the past (other thread), and there are some recollections and opinions out there, but I have struggled to find much in the way of concrete reference material to answer my questions, so I thought I would start here. I have also sent a couple of questions to https://www.raffca.org.uk/ in the hope that someone there may be able to help too.

A.R.I. 18168 aircraft installation consisted of:

• PTR-177 V/UHF radio T/R unit (in lieu of the PTR-175)
• Signal Data Converter
• Selector Address unit
• Head Sound Reproducer

I so far have written up what I have find out about Data Link and Lightnings here: https://scottbouch.com/mcfs/lightnin...-data-link.htm which is mainly aircraft-oriented, not having much information from ground radar stations. I'm looking to fill in the blanks by asking specific questions, as the other thread is mainly broad stroke comments.

My questions are:

A) If Data Link was just trialled:

1. What dates/years was the trial conducted?
2. Which units/squadrons conducted the trial?
3. Why did it fail to enter service fully?
4. What did aircrew think/feel about the pre-recorded voice commands? I have a distant memory of an ex-RAF pilot telling me the "robot voice" telling them what to do was disliked, just can't recall who told me.
5. If the Data Link system was capable of flying the aircraft via the Flight Control System/Autopilot, how did the aircrew feel about this, being at someone else's mercy?
6. Is it true that the space left where the Signal Data Converter would have been installed was used for kit bags? And/or discreet "duty-free" imports?

B) Technical questions:

1. Did the RAF Lightning Data Link use the "Link4" standard? (reference)
2. The "Head Sound Reproducer" unit was the tape player that passed voice commands to the aircrew headsets; was this a male or female voice?
3. Is there a list of these recorded voice commands anywhere?
4. Has anyone got a Head Sound Reproducer knocking around anywhere with tape still inside? (If so, could I get it working?)
5. As command/target data was able to be presented by the IFIS (Integrated Flight Information System) flight instruments, was the Flight Director bead of the attitude indicator able to be controlled by Data Link?
6. If 5 is a 'yes', then was the Flight Control System / Auto Pilot also able to fly the aircraft based on Data Link commands? ie: pilot hands-off.
7. Does anyone have any AP's detailing ARI 18168? Or other related information?
8. Are there any ex-Lightning pilots who still have any flight log books who may have worked on the trials? May be able to find some dates out..

Other aircraft:
I once spoke to a ground radar engineer who told me the RAF F4 Phantom also was compatible with Data Link, however, I don't know if this was in service, or just trials. I can't find any evidence of it in my Buccaneer S2 Vol1 AP's.

I probably will have many more questions as time goes on, but if anyone can answer any of these, or indeed throw any other thoughts into the melting pot, I'd really appreciate it. Ideally I'm looking for specifics rather than generalisations (and indeed documented evidence is king of all), but I will gladly listen to anything that anyone can recall! You may know an answer to a question I've not asked, so please do throw it in!

If I have made any mistakes / bloopers in the web page I've written, please do let me know! I'm trying to keep it factual and show my research.

Many thanks, Scott.